What obligations do highly public developers have to their users?
I assume from the context that you mean social obligations that are somehow related to their being developers. That is, you're not talking about the general social normative obligations that apply to everyone: for instance, to not commit fraud or slander. Nor, I assume, are you asking about obligations of software developers to not produce malware, and so on.
Developers do not have any additional social obligation to their users that I'm aware of. Is there something special about developers that would require different social obligations to be imposed on them?
Does their obligation increase with prestige?
Famous musicians are not obligated to make music you like, no matter how famous they are.
Famous authors are not obligated to write books you like, no matter how famous they are.
Famous actors are not obligated to make films you like, no matter how famous they are.
Why would a famous software developer be obligated to make software or software documentation you like?